<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<div id="app">

    {{ msg }}
    <div v-if="error">页面加载错误</div>

    <div>
        <input type="text" v-model="score">
    </div>

    <div v-if="score>=60">及格</div>
    <div v-else="score>=60">不及格</div>
</div>
<script src="https://unpkg.com/vue"></script>
<script>
    var app = new Vue({
        el:'#app',
        data:{
            msg:'hello world',
            error:true,
            score:52
        }
    })
</script>
</body>
</html>